Traffic signal



Jan. 14, 1930.. A O, OLAFSON 1,743,383

TRAFFIC S IGNAL Filed Nov. 18, 1927 2 Sheets-Sheet 1 o 0 O B A. ofoLAFsoN TRAFFI C S IGNAL Jan. 14,' 1930.

Filed Nov. 18, 1927 2 Sheets-Sheet `2 Patented Jan. 14, 1930 UNITED .STATES PATENT OFFICE ALVIN O. OLAFSON, OF ST. PAUL, MINNESOTA, ASSIGNR, BY DIRECT AND MESNE AS- SIGNMENTS, TO 'NATIONAL TRAFFIC SIGNAL COMPANY, OF ST. PAULr MINNESOTA.

A CORPORATION OF MINNESOTA TRAFFIC SIGNAL Application led November 18,1192?. Serial No. 234,168.

My invention relates to a signal particularly adapted to indicate the stop and go to traflic at intersections. A primary feature of the invention resides in a means adapted to indicate by a clearly visible means, the approximate time of the change of the traflic signal which is visible either in the daytime or at night to indicate the approximate time before the signal will change.

It is also a feature of the invention to provide means of a curtain-like nature which is adapted to be operated by time mechanism in a manner to cause the. curtain to gradually shutoff a light which. indicates the change of the signal.

My signal includes a means of indicating on two or more sides a streak of light so as to indicate in accordance with the size of the streakof light how much time remains before the signal will change. As the signal approaches the changing period the signal light vis gradually shut off until it is entirely invisible momentarily just as the signal changes to change the direction at street intersections.

I include in my invention a means of diffusing the light at a point adjacent the screening curtain which causes the curtain to give a clear shadow either during the day or at night, and even in the sunshine.

My signal includes a transmission which may be readily changed for'difi'erent .speeds together with a suitable timing means which may be' adjusted or set as may be desired to change the time of the operating curtain signal.

I also provide means for dampering the drop of the lcurtain which is an important feature of my invention.

These objects, together with other details and features will be more fully and clearly set forth in the specification and claims.

In the drawings forming part of my specification:

Figure 1 indicates a perspective View of my signal as it would appear in use.

Figure 2 is a detail of aportion of the same. lliigure 3 is a detail of a portion of my signa Figure 4 is a detail of the signal.

Figure 5 is a section on the line 5-5 of Figure 1.

Figure 6 is a plan view of the signal head.

Figure 7 is a detail of one of the adjustable lifters.

Figure 8 is a side sectional view of my signal.

Figure 9 is an 'enlarged detail partly in section.

Figure 10 is-an enlarged detail partly in section.

Figure 11 is a cross section.

Figure 12 is a detail of a lifting chain and lifter.

My signal A is designed to provide anup right signal having side Walls 1G and corner members 11. The side Walls 1 0" are provided with signal indicating openings 12 and these openings may be formedn two or more sides of the side walls. The openings 12 may be covered with glass oi'- other suitable material 'to in'close the inner parts of the signal A.

The signal A is formed with a signal head B having openings 13 adapted to 4indicate the direction of travel of the traic bv suitable colors such as red and green, the red color indicating a stop and the green the go, or the openings 13 may indicate the Words Stop and Ga portion of the Within the sides 10 which form the casing i Vlight coming with a long bearing or support 18, I 'provide a means of supporting the intermediate gear 19. p The gear 19 is adapted to mesh with one of the gears 15 and b changing the size of the gear 19 as indicate in dotted outline on the shaft '17 the speed of the transmission C may be varied. The line of drive from the motor D extends through the gears 20 to theshaft 16 which in turn drives the shaft 17 through the gears 21 and from'thence through the gear 19 to one of the gears 15 Vwhich operates the 'gears 22. One of the gears 22 is connected by means of aI sprocket 23 which drives the lifting chain 24.-l A

I provide a suitable shelf 25 for the extra gears 19 so` that my si al is all self-contained and any time that it-1s desired to change the speed of the operation of the same it is only necessary to take a diferent size gear 19 from the shelf 25 and place it in the transmission C in such a manner as to mesh with the proper gear 15.4

The lifting chain 24 travels from the sprocket 23 and over the idle pulleys 2610- cated near the top of the signal A. This liftin chain 24 is adapted to receive lifters 27 w ich include spring fingers 28 adapted to engage over the pins of the chain 24 as indicated in Figure 9 and which are provided with a lifting 1roller29. The lifters 27 can l be snapped onto anylink of the chain 24. Y

Thus the lifters may be changed in position on the chain and by placing these lifters at different pointson the chain the timin of the curtain signal is regulated. This wi 1- be more full hereinafter described.

I provi e a Vseries of electric lights 30 within my signal A which extend along the openings 12 so as to provide a sufficiently strong light for the o enin 12 to provide an indicating light ada tags to indicate the change of the signal. he lights 30 may be of a frosted nature, however, I prefer to provide translucent diifusng screen plates 31 spaced from the lights 30 and'which are hung from the top shelf 32 by means vof the clas s 33 so that the translucent shields 31 will di use the light from the electric bulbs 30 in a proper manner within thesignal A.

I (provide'a curtain 35 in my signal A which 1s a apted to fact in apmanner to shut off the through the openings 12 in the operation o the signal A. The curtain 35 is Yoperated by thev lifters 27 which engage against the shoulderf member 36 formed at the top .edge of the rcurtain 35. As the transmission C .is voperated and the lifting` chain 24 carries the lifters 27 into engagement with the shoulder 36, the curtain 35 is ylifted in a manner to curtain off the li ht coming through the openings 12. The lifting chain 24 operates in a timed manner so as to slowly lift the curtain 35 and thus the signal light which is ada ted to indicate the time of change throng the Aopenings 12 iai-gradually shut off as the curtain 35 is lifted. When the -38 which'is pivotally. mounted to' the vface plate 39. One end of the check arm 38 is curved at 40 to form a bearing end .which is adapted toengage against the leather cushionx 41 whichl is .attached to the inside of the curtain 35 on one side. The check/E is formed-With a spring 42 which normally holds the bearing end Vout of engagement with the side ofthe vcurtainf35. The bearing arm 38 is also formed with a brace portion 43 extending between the bearing end 40 and the free end 44. The curtain 35 is provided with a shoulder member 45 whichis'positioned in such a manner as to engage against the free end 44 of the arm 38 as the curtain 35 drops from its elevatedY position to its lowermost position. Thus as the curtain 35 falls to low-V ermost position `it does not strike with itsl dropping force'againstthe bottom of the signal A, but is engaged' by the damper E in a manner to retard and damper the fall'of the same just before the curtain strikes the bottom of the inside of the'signal A, thus effectually retarding the drop of the curtain and protecting the same Yagainst-undue wear. VThe coil spring 42 releases the check E the moment the curtain is lifted by the lifter 27. .4

The lights through the openingsw12 are adapted to provide signal lights indicating the change of the signal. The length of the light through the openings 12 indicates the approximate time of change of the sigvnal Ain proportion ofthe travel of the screening curtain '35.

The diffusing screen plates 31 may be easily removed by disengaging the saine from the shelf 32 tov replace the lights30. Thesel screens .diffuse the light from the lamps 30 A.

so that a sharp defined shadow or yline is effected from the top edge 48 of the curtain 35. and'appears through the openings 12 y at night or even in the sunlight to -clearly indicate the the signal A.

I .provide a guard arm 49`ii1 the curtain 35 which holds the chain 24 into engagement with the shoulder 36 even`thougl1 the chain mayhvibrate some in its operation.Y

e sigma' had B is adapted to iadica position1 of lthe curtain 35 in g accomplished by color or by the wording\ itself. I have shown in the drawings a means of indicating the direction of travel'in the head B. This includes a rotatable'frame 50 which is supported within the head B by the shaft 51 upon which the frame 50 is adapted to rotate. The shaft 51 is held by the nut The frame y50 is adapted to support a series of lenses 5,3 which may be of red and green color or which may carry the words Stop and Go to indicate to the traffic the direction of travel and to indicate stop and go of the same. rIhe lenses 53 may be of a exible nature such as celluloid or other suitable colored translucent material and may be held by the grooves 54 formed in the frame 50 so that the lenses 53 may be removed when it is desired. x

W ithin the frame 50 I provide an electric light socket 55 which is adapted to carry a signal light for the signalling head B, to indicate the signal through the openings 13. Figure 3 illustrates the head 50 with one of the lenses 53 removed so that the signal light can be placed within the socket 55.

The top of the frame 50 is formed with a collar having depending teeth 56'which engage against the pin 57 to direct the frame in a rotary movement as it is lifted on the shaft 51. One side of the teeth 56 inclines at an angle, whileY the other side is comparatively straight longitudinally with the shaft 51.

The bottom of the frame'50 is provided with inclined arms 58 which are adapted to be engaged by the lifting pin 59 carried by the curtain 35, as the curtain is elevated. I provide a guiding pin 60 projecting from the shelf 32 which holds the frame 50 against rotation in the first period of its lifting on the shaft 51 by means of the lifting pin 59. This pin 60 steadies the frame 50 so that it Will not bind on the shaft 51 and prevents rotation until it has been elevated to a predetermied point, so that when it is released fromthe pin 60, the arm 58, owing to the `angular nature of the same, will cause the frame 50 to rotate on the shaft 51 and the inclined surfaces of the teeth 56 engaging Aagainst the pin 57 will cause the frame 50 to rotate a quarter turn, changing the position of the lenses 53.

Thusl as the curtain which indicates the time of change of the signal head B reaches its uppermost position shutting off the light from the windows or openings 12, the frame 50 is operated, operating the signal head B to change the indicating direction to 4the traffic. It is therefore apparent that if the two opposite lenses 53 are green and the other two diametricallyA opposite `lenses are red, that the signal head B will indicate through the openings 13 Stop by the red light to one by the green direction of travel, and Go t travel. It is light to the other direction of further apparent that the curtain 35 will act in the sense of a thermometer indicator, gradually shutting olf the light through the openings 12 so that as the motorist'or pedestrian` approaches the signal A they can see very clearly the approximate time of change 'of the signal A. The signal is adapted to ,opcrate automatically to change the direction indicator in the head B by means of the operation of the curtain 35. The change of the indicating head B is simultaneous with the operation of the curtain 35 at the moment the curtain reaches its uppermost position. The

light from the openings 12 is only shut off momentarily and by means of my signal I believe a more practical indicator is provided than heretofore, by virtue of the time indicating curtain which indicates the approximate time of change of the signalhead B. The position of the curtain indicates at all times the approximate time of change ofthe head B.

v'Ihe adjustment of the lifters 27 to different positions on the chain 24 permits the signal to 'be so set that the intervals between the time of lifting of the curtain 35 may be lengthened or shortened so that a longer or shorter time may be set for the travel of traffic in one direction or the other and the transmission C may be set to operate the signal slow or fast so that Iprovide a signal adjustable and variable as to speed and time in a very simple and effective manner. v

It is an important feature of my invention to provide a means for indicating the time of change of the signal byv a moving element which is clearly visible day ornight and even in the sunlight. I accomplishy this by the particular means set forth. I believe mysignal in its simple operation and clearly visible Vthermometer-like indicator provides to the trafiic a more simple and effective means of signalling. This is particularly true' when considering that if the pedestrians and autoists know just exactly when the signal is going to chan'ge, lessconfusion will arise and thus I believe accidents may be avoided.

In accordance with the'patent statutes I l nal light, and a curtain for gradually shutf ting olf said change signal light.

2. A signal including, stop and go indicating means, a change signal means, curtain means for gradually shutting of said chan signal means to diminish and completel; shut if the same, means for releasing the curtain to permit the saine to drop, and retard' means operable bythe dropping force o the curtain to retard and prevent A rebound of the same.

l' ard, a signal signal light associated with the stop and go signal, a curtain for -shutting olf the change signal light, and a transmission adapted to vary thespeed of the operation of the cur- 5. A including, stop and o meansk for a change signal lig' t,va curtain .or ually shut-ting of said change signal light, means for o rating said curtain at variable speeds, an means for retarding and preventing rebound of said curtain in the fall of the same.

6. A trailic signal including, a standard, a signal light at the top of said standard adapted to indicate stop and a change signal light below said stopl an go signal means, a curtain for gradually shutting of said` change signal light, and ad]ustable means for operati said curtain to vary the time of lifting e same to permit the curtain to be lifted in a manner 'so as to provide long and short intervals in the o ration of the same.

7. A lincu ,astopandgosignal light, a curtain .for

light, a c ange 4signal light, means shutting of said c a carried by said curtain for operating said sto and alli ht to chan e the direc- 'tiorli of tlsgt thie; .moment gf said curtain reaching the limit of travel in one direction at the time of shutting off the change signal light, and means'for timing the opera- A tion of said curtain to provide long and short intervals between the stop and go tramo.

V8. A trailic signal com rising, a standard, a stop and go signal in t e head thereof including a rotatable lens carrying member,

^ means for operating said lens carrying memmal ' holding member non-rotatably during the ber to rotate the saine by lifting and cause the same to rotate whenV gravitating t o nor- 'tion, and means for holding said lens lifting operation thereof.

, 9. VA ttatlicsignal comprising, a rotatable lens member adapted to indicate stop and go by similar colors on diametrically opposite sides, and means for supporting said memberto permit the same to be lifted. and then rotated to a changed position in its movement by gravity to normal position.

er adapted to be adjusted to vary the timing 'of the lift of said curtain means.

11. A trailic signal including, a signalling head, a signal change indicator, a curtain for screening the indicator, lights for illuminating the indicator, diffusing means inter-v posed between the lights and curtain to cause the curtain to form a sharp defined line of indication at night and in the sunlight.

f l 12. A traiic signal including, a signal light, a curtain for screening the light and means for diffusing the light in relation to the curtain so as to cause the curtain to be sharply defined in the outerappearance of the same in daylight and at night,

13, A traiic signal including, a-signal light, a curtain for screening the light, and means for diffusing the lightin relation to the curtain so as to cause the curtain tobe sharply defined in the outer appearance ofthe same in daylight and at night.

14. A traic signal including. aVA casing, a signalling means within said casing, a trans'- mlssion Within said casing, a motor for operating said transmission, a curtain surroundi.

` ing'said transmission and slidably sitioned within said casing, a chain operab e by said transmission, an ad'ustable lifter means carried by said chain adapted to engage said curtain to lift the same, said curtain being adapted to betimed by said transmission and lifting means to operate to screen oif said signalling means. v

15. A traliic signal comprising a casing, a signal head in the top of said casing, a signalling c linder rotatably mounted in said head, a s idable curtain operable below said head, a transmission and 'lifting means adapted to operate saidcurtain, openings in said casing in said head to indicate the direction l of travel of traffic, elongated openings below said head extending longitudinally of said casing which are adapted'to be screened by said curtain-in the operation thereof, means operable with said curtain and signalling cylinder adapted to cause said cylindervto opcrate simultaneously with said curtain at the prevent the curtain from dropping with undue force.

17. A traflic signal including, signalling means adapted to indicate stop and go, means adapted to indicate' the time of change of said stop and go signal means including curtain means for screening said indicating means, means for operating said curtain in a manner to move the same to a predetermined position and release the curtain causing it to fall, and means adapted to retard the fall and rebound of the curtain when released.

ALVIN O. OLAFSON. 

